金龟子绿僵菌附着胞分化及其与环腺苷酸cAMP的关联性研究_英文_

M ycosystema

菌 物 学 报 15 September 2009, 28(5): 712-717

jwxt@

ISSN1672-6472 CN11-5180Q

©2009 Institute of Microbiology, CAS, all rights reserved.

Appressorial differentiation and its association with cAMP in the insect pathogenic fungus Metarhizium anisopliae

DUAN Zhi-Bing1 GAO Qiang1 LU Ding-Ding1 SHI Shao-Hua1BUTT Tariq M.2WANG Cheng-Shu1*

1Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China

2School of Biological Sciences, University of Wales Swansea, Swansea SA2 8PP, UK

Abstract: Host recognition and appressorium differentiation are the pivotal steps for insect pathogenic fungi to initiate infection process. In this study, appressorial differentiation was studied by comparing a mutant, which has been identified with the loss of genetic materials, with the wild-type strain of the insect pathogenic fungus Metarhizium anisopliae. The observations showed that both the mutant and wild-type strain could not only produce appressoria on the tips of newly germinated spores, but also form multiple infection structures from the terminals of branching mycelia on insect cuticle. In contrast to the wild-type, the frequency of appressorial formation was significantly reduced and in addition, no clear mucilaginous sheath was produced by the mutant appressoria. The study shows that the cuticle degrading enzyme subtilisin is not involved in appressorial differentiation, or indispensable in cuticle digestion. A significantly low frequency of appressorial differentiation by the mutant was coincided with its lower intracellular cAMP level in comparison to the wild-type. Addition of exogenous cAMP could significantly increase the frequency of appressorial differentiation by the mutant, indicating that cAMP signaling pathway is potentially involved in regulation

of appressorial differentiation in M. anisopliae.

Key words: insect pathogenic fungus, cuticle penetration, mucilaginous sheath, subtilisin

金龟子绿僵菌附着胞分化及其与环腺苷酸cAMP的关联性研究

段志兵1 高强1 吕丁丁1 石少华1 BUTT Tariq M.2 王成树1*

1中国科学院上海生命科学研究院植物生理生态研究所 上海 200032

2School of Biological Sciences, University of Wales Swansea, Swansea SA2 8PP, UK

摘要：寄主识别与附着胞分化是虫生真菌启动侵染过程的首要步骤。本文利用先前获得的金龟子绿僵菌基因缺失突变株与

其野生型一起进行附着胞分化研究。接种后不同时间下的观察表明，绿僵菌突变株或野生型的附着胞既可以在萌发不久的芽

管顶端形成，也可以在伸长菌丝分支的顶端形成。与野生型不同的是，突变株附着胞的分化频率显著下降，附着胞周围也缺

Supported by The Knowledge Innovation Program of CAS (No. KSCX2-YW-G-037) and the Science and Technology Commission of Shanghai Municipality (No. 07PJ14101)

*Corresponding author. E-mail: cswang@

Received: 11-12-2008, accepted: 06-02-2009